Wireless-telegraph apparatus.



v v. I PATENTEE SEPT. 8 190s.

N 89819 E. EUNWo-ODY.

WIRELESS TELEGEAPE APPARATUS.

APPLHJATION FILED MAY 21, 1907.

4 SHEETS-SHEET 1.

I I I r l l @XH/Imaam@ 3mm/hoz N.s 197. PA-TENTBD sms 190s.

98 H.DUNW00DY.

WIRELESS TELEGRAPH APPARATUS. APPLIOATION FILED MAY 21, 1907.

4 SHEETS-SHEET 2.

HozueiJ v PATENTED SEPT. 8, 1908. H. DUNWOODY. WIRELESS TELEGRAPH APPARATUS.

APPLICATION FILED MAY 21, 1907.v

4 SHEETSjSHEET 3.

S14/WMO;

N0. 898,197. i PATENTED SEPT. 8, 1908. H. DUN WOODY. WIRELESS TELEGRAPH APPARATUS. APPLIoATIoN FILED MAY 21, 1907.

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- Juventaz Witnesses hand these out rUNITED srerns PATENT entren.

HALSEY DUNWOODY, OF THE UNITED STATES ARMY.

WIRE LE SS-TELE GRAPH APPARATUS.

Specification of Letters Patent.

Patented sept. a, 1908.

Application filed May 21, 1907. Serial No. 374,944.

art to which it appertains to make and .use`

the same.

` My invention relates to wireless signaling apparatus and especially to a wireless telegraphic or radio electric apparatus of a portable character.

The object of my invention is to improve the art in general and also to produce a prac,- tical portable wireless telegraphic apparatus which shall be capable of sending and receiving messages with unerring certainty for distances of from twenty to one hundred miles and over and, yet, shall be so light as to be capable of being carried by two or even one man, and which requires so little space that the whole may be packed in a box not.

larger than an ordinary valise.

Portable wireless outfits, heretofore pro- ,-duced, capable of sending and receiving messages wit certainty, overthe distance my invention covers, have been of a much heavier character, requiring the use of pack animals, automobiles', or other e uivalent moans of trans ortation, while on t e other fits of a light character capable of being carried by one or two men, have been of the character of models, and small demonstration apparatus, and in every instance, they have been incapable of operating in actual practice over the distances readily covcredby my device.

The advantages of a practical ortable wireless apparatus capable of covering from twenty to one hundred miles and over and capable of being carried by two or even onel man, in the field of battle, in campaigns, or maneuvers, in surveying and other similar operations, and ada ted for use on gun boats,

Itorpedo boats, yac its and crafts of similar nature, are a parent; especially, when it is remembered t at at the supreme'moment, in a battle for instance, it might be im erative that the wireless equipment be oapab e of being readily moved about by one-or two men;` and occasions could arise when the same able, in maneuvers, or campai ns, or' in surveying parties ex loing a roug country and far from base. hen, again, it is of no small importance'to have such a light apparatus 60 when moving the same off and on yachts, .torpedo boats, and small craft, especially when lit is desired to carry such apparatus to and from said craft at any time, and in a row boat without danger of losing it overboard during the act of lifting it from theboat toA the vessel. f f,

I attain my Aobject of improving the art generally by introducing into existing sys-- tems certain new features, described more particularly hereinafter, and I produce my ight portable apparatus by omitting certain parts of existing apparatus therefrom and in introducing therein these said new features combined with others, all as more fully described below.

To these ends, my invention consists in a wireless -telegraphic apparatus of any kind whatsoever, having an aerial from one side of a spark, ap to an electrical current separator or rectifier, and thence to ground, and constituting an efficient sending and receiving antenna.'

My invention, also, consists in providing a wireless apparatus of any kind with a recelver normally in direct or shunt circuit with the4 transmitter, thereby lessening the weight and causing the wiring to be very much more simple, and doing away with much that is now used in the ordinary systems.- i My invention further consists in producing an .efficient current separator or rectifier use. ful in this art, generally, but especially useful in any portable set.

My invention further consists in providing a portable set with certain of the above features, and in eliminating other well known features heretofore considered essential for a practical field apparatus, and in thereby roducing aepractical field apparatus which believe is verymuch lighter than any heretofore produced, all as will be more fully herein described and particularly pointed out in the claims.

Referring to the' accompanying drawings forming a part of this specification z-Figure 1 is a perspective view of the box with my portable set ready for operation. Fig. 2 is a diagram of the circuits of said set. Fig. 3 is a view of sending and receiving i'nductance coils that are found useful to the apparatus would be true, or at least very highly desirshown in Figs. 1 and 2, when the operating y for containing these commercia distances are to reach one hundred miles or over. Fig. 4 is a diagram of the circuits when the inductance coils, shown in Fig. 3, are employed. Fig. 5 is a diagram of my new antenna and modiiied spark gap. Figs. 6 and 7 are details of my current separator or rectiiier. Fig. 8 is a diagram of another modiiied receiving circuit.-

9 is a diagram of a modified sending circuit showing my new interrupter.

Like letters of reference refer to like parts in all the views A indicates the boX containin my portable wireless telegraphic outfit, W `ch, when complete for operatlng over distances from 20 to 100 miles, need not be larger than an ordinary valise, nor weigh more than, say, 150 pounds.

B indicates the casing carrying the transmitting battery C, and which may be storageY cells or other source of power and need not be more than six or eight dry cells, and D the magneto spring interrupter of the ordinary spark induction coil E, such as is now used in automobiles and small boats.

F represents the primary, andG `the secondary, of this coil. Across the terminals of the primary F, is joined the small light condenser H, and across the terminals of the secondary G is joined the similar small and light condenser I.

J represents a casing placed in the box A parts, andK the'\ad justable sending spar gap, or other wave generator or transmitter.

L represents the direct wire connection through the double throw switch M between the spark gap K and the aerial N. This aerial or antenna N, may be formed of a very iine thread-like wire capable of being suspended by any ordinary-stationary means,

or even by a small gas balloon, or kite, or it may be com 'osed of an uninsulated heavier wire, and it eads to the current separator P, through the auxiliary spark gap O, although in some cases this gap may be omitted. The

current selprator or rectiiier P, may be of any well own construction, but I prefer one of my own which in practice has proved itself far superior to any others. It 1s composed .of one' or more crystals of carborundum, P7, Ps, as shown in detail in Figs. 6 and 7, preferably one, sealed in a vacuum tube P6, which in turn screws in and outl a socket like an electric lamp bulb. The carborundum in the tube is connected to earth at R by wire Q.- By the use of this separator P, I am enabled to entirely dispense with the usual inductance'coils for dlstances of twenty miles and over, and for distances upto one hundred iles and over, I need use only very light inductancesof one of the forms more fully described below. This construction for twenty mile distances, permits the wiring to run dlrectly from Athe spark gap to the double throw switch, the aerial, the separator P, and through the same to ground, and

and the efficiency of said apparatus is not at all destroyed by such lightening, when used over the distances stated.

The receiving circuit .for this apparatus consists of the Wire S running from the double throw switch M as' shown, to the oint T,

Where it connects With the wire which from the oint T runs through the telephone receiver to the local battery Y inclosed in the case X, thence to the adjustable resistance A',- which may be a bar of carbon with a sliding contact, as shown in Fig. 1, to the point B', and to ground. The point B is connected with the responder C', inclosed in the casin Z, as well as the point T. This res onder maybe of any suitable type, but

prefer to emiloy a very simple and eflicient one, compose of one or more cr stals of carborundum, substantially as disc osed in Patent, No. 837,616, Dec. 4, 1906, to H. C. Dunwoody, butin this instance, sealed in a vacuum tube, which may be readily screwed in and out of a socket, like an incandescent lam bulb.

T at side of the spark ga not connected to the aerial, is grounded t rough the Wire D', as shown.

E represents an ordinary telegraph key not specially insulated for controlling the primary circuit as shown.

The operation of the device so far described is as follows ,In order to send, the operator throws switch M to the right and makes and breaks circuit with the key E', in the primary circuit of the s ark coil E, which causescorresponding spar s to pass at 'the ap K, and ether waves to traverse, and be t own off, the wire L and aerial N, allas is Well known. The alternating current passing through the current separator P to ground and back is, I believe, rectified. That is to say, one wave, sup ose, for instance, the plus, robably, gets t rough the separator P, and t enegative does not, then the ether vibrations or radio electric oscillations or waves are probably caused, and augmented, by that portion of the current that is dammed up, so to speak, between the current separator or rectlier and spark gap, while'the ether wave of th current passes through the rectiier and is umped, as it were, into the ground at every t rob. It is also highly probable that this action lowers the resistance of the intervening spark gap O between the transmitting and receiving antenna and makes use of the earth as well as of the ether as a transmitting medium. I do not bind myself,

however, to any particular theory of operation of this part of my invention nor to any `particular compound or substance for pro- And ducing this most remarkable result.

while I have found the carbids of silicon aluminum or carborundum to be well adapted for this purpose, I reserve the right to em.

ploy any current rectifier, whatever, or other j V the same, to be. far stronger to send and clearer to receive, than those produced with-q out the aid of my 'se arator, and, therefore, I believe some distur ance isset'up through the agency of my separator, which creates a greater and cleaner cut, so to speak, vibration of the ether,or transmitting medium, than has been attained heretofore, with the same transmitting power. w

The receiving circuit is completed by throwing the switch M to the left, and ether waves striking the antenna will be directed down the wire S to the responder C and the resistance of` the same being changed thereby, signals will beheard in the, telephoneW, in the manner well known. But,.1n this in` stance, owin to the use of my rectifier, or separator P, have discovered that the signals are far stronger and clearer, as above stated, :than is attained by any other instruments with which I Vam acquainted. This greater clearness and distinctness in sending 'and r. ceiving enables me to use :a much lighte transmitter or sparking apparatus than any heretofore found racticable for the same distances cvere including a lighter source of power .and other parts. The result is, my separator is not only a most important factor in lightening my portable apparatus, but' the arrangement comprises a most efcient sending .and receivin antenna for general use, Whether in aportalgile set, or

' not, and vone which constitutes a marked imthe most ample practical experience and exhaustive experiments, I Ahave become convinced thatfit is very questionable whether or not the air gap, as heretofore used, accompli'shes any useful purposes; but there can be no doubt, whatever, about my system accomplishing its purpose. I do not think that the rectifier or separator P, can he considered able app aratus.

an insulator, nor that the antenna can be considered insulated, for that portion of the antenna from the rectifier to the ground is fully charged at every throb.

The above apparatus taken as a whole constitutes a portable set weighing about 150 A pounds or less, and is capab e of sending and receivin messages' with clearness and certainty o? about twenty miles or over. 'If the distance is to be increased say up to one hundred miles or over, as above stated/I find it convenient to add two small adjustable ini ductances, G', H in the sending and receiving circuits respectively, as shown in Fig. 3 and in diagram in Fig 4. These inductances may be conveniently carried on the back of the box' as shown in dotted lines in Fig. 1, and connected to the spark gap by wire G.

The sending inductance G is composed of a light coil of lightly insulated heavy Wire, with a sliding contact. It can be made light owing to the fact that the transmitting voltage on this portable apparatus is no t sufiicient to pierce the light insulation employed. The receiving coil H, is made of ne insulated wire with a similar sliding single contact, in which particulars it differs from all other coils with which 'I am acquainted that have been heretofore used for this purpose. It is found convenient in regulating waves coming from great distances to employ this coil so that the receiving apparatuswill readily respond to varying .wave lengths. When desiringto use these coils, connection is' made to wirel G with one side of the spark gap, Yand at H with the responder as shown in Fig. 1, the apparatus is then operated as abovedescribed, and the inductances are adjusted until the best results are obtained.

In Fig. 5, I'have diagrammatically illustrated/ansfantenna for general use and which in practice/I. have found to give'"'excellent results, when'joined up with my rectifier, it being .also well adapted for use with my port- In this figure Kl', represents a suitable spark gap, L a suitable inductance i coil having two sliding connections as shown,

M an auxiliary spark gap, and N, a connecting wire supported by any suitable means, as for example, by the same supports 'on which the spark gap M is mounted, as

shown.'v O represents the antenna, P my current separator, or rectifier, Q the connection to ground, and R the point at which the connection is made.

In operation the distance between the two connections' on the coil L is varied until a spark of the greatest length possible is obtained at gap M. This will occur when the maximum energy is passing. Then this gia is close-d until it just touches or fails to touc the connecting wire N, and the apparatus is ready for use. i By this means with the gap adjusted as described, I know when\ using this antenna, that I am causinga maximum of energy to flow into my antenna, and I find it a much moresatisfactory and accurate means of ascertaining this'fact than the hot wire ammeters heretofore employed. Furthermore, in my experimentswith this a paratus I have discovered that it not on y possesses marked advantages over the old style antenna in transmittin', but also in receiving, because the static e ect in this case and in the others above mentioned is almost reduced to zero, for the reason .that the an tenna is directly grounded through the rectifier. The im ortance of this feature of my invention will) be recognized, when it is remembered that static effectsconstitute one of the greatest obstacles at the present day to the efficiency ofwireless telegraphy.

In Fig. 9 I have shown animproved interrupter for my spark coil. I have found that one of the secrets of ortable wireless sets is to get a perfectly acting interrupter. In the ordinary sparkA coils -the interrupter contin ually has to start and sto and works only while the sending key is own. In m improved device the interrupter acts al the time the set is being used, so it does not have continually to start and stop, andthe improved results follow at once. In a portable set this is of great importance, for since it causes the sending to be more certain, other parts can be made more lightly and still be relied on to do the work.

To one side of the primary F of my spark coil, shown in Fig.'1, I connect the Sending key E as shown in Fig. 9, and to the pivot of'this key I connect one side of the battery C. To theother side of said battery is connected the wire G, which in turn is corinected to the electromagnet I. This electromagnet is connected to the fixed end K of the spring'controlled armature L normally touching the contact M, which -in turn is connected with the otlferside of the primary coil F and through-'theJ same, to the key, as shown.

From .the foregoing disclosures it Vwill bel seen that I have' roduced several distinct p improvements app icable to the wireless telefrom twenty to one hundred miles or more.l

Having thus described myjinvention, what I claim and desire to secure by Letters Patent is 1. In a radio electric circuit, the combina'- i tion of an aerial, means to impress oscilla tions thereon, and a current rectifier or separator in said aerial, substantially as described.

2. In a radio electric circuit, the 'combina- I tioii of` an oscillating circuit having an aerial,

means to impress oscillations thereon, a ground connection for the same, and a current separator or rectifier connected with said aerial, substantially as described.

3. `In a wireless telegraphic apparatus, the combination of a sending spark gap, an aerial, a ground connection for the same, and a current se arator or rectifier in said aerial between said) transmitter and said ground.

4. In a wireless telegraphic apparatus, the combination of a wave transmitter, an aerial connected with the same, a ground connection for said aerial, and a current se arator or rectifier containing silicon, in sai aerial between said transmitter and said ground, substantially as described. f, r

5. In a wireless telegraphic apparatus, the combination of a wave transmitter, an aerial connected with the same, a ground connection for said aerial, and a current se arator or rectifier containing silicon and car on, in said aerial between said transmitter and said ground, substantially as described. A

6. In a wireless telegraphic apparatus, the combination of a wave transmitter, an aferial connected with thelsame, a ground connection for said aerial, and a current se arator or rectifier composed of carborun um or silicon carbid in said aerial between said transmitter and said ground, substantially as described.

' 7. In a wireless telegraphic apparatus, the combination of a suitable wave transmitter, an aerial, an air ga in the saine, a ground connection for sai aerial, and a' current rectifier or separator in said aerial between said ground and said transmitter, substantially as described.

8. In a wireless telegraphic apparatus, the combination of a suitable wave transmitter, arr aeriai, an air ga in the same, a ground connection for sai aerial, and a current rectifier or separator composed of carborundum in said aerial between said ground and said transmitter, substantially as described.

9. In a wireless telegraphic apparatus, the combination of a suitable wave transmitter, an aerial, a ground connection for-said aerial, and a current rectifier or separator in said aerial between said ground and said transmitter, said separator constituting the sole path for the cur ent from said aerial and to.

its ground, sub antially as described.

10. In a wireless telegraphic apparatus, the combination of a wave transmitter, ari aerial, a round 1for the sarrie.a current separator in the same composed essentially of carborundum Land located between said transmitter andsaid ground, substantially as described. f v

11. In a wirelesstelegraphic apparatus, the combination ofv a wave transmitter, an aerial, a round for the saine, a current separator' in the same composed essentially of carborundum sealed ina vacuum tube, and located between said transmitter and said ground, substantially as described.

12. Iii a wireless telegraphic apparatus, a sending aerial provided with a current separator composed essentially. of carborundum,.substant1ally as described.

13. In a wireless telegraphic apparatus, a sending and receiving aerial provided with a curient separator composed essentially of carborundum and at all times grounded through the same, substantially as described.

14. In a portable wireless telegraphic apparatus, the combination of a spark gap, a sending and receiving aerial connected directly to the same, a ground for said aerial, and a current :separator aconnected to said aerial and .between said gap and ground, thereby causing said aerial to have a distinctive tone in sending, and therefore rendering the use of a tuner unnecessary, and thereby lightening and simplifying the wiring of the apparatus, substantially as described.

15. In a portable Wireless telegra hic apparatus, the combination of a spar gap, a sending and receiving aerial connected directly to the same, a ground for said aerial, and a current separator connected to said aerial anddirectly connected to saidfground, thereby causing said aerial to have a distinctive tone in sending and receiving, and

.therefore rendering the use of inductance coils for tuning and for regulating the wave lengths unnecessary, and thereby lightening the apparatus,y substantially as described.

16. In a portable wireless telegraphic apparatus capable of sending and receiving messages fordistances of twenty miles Vand over, the' combination of a spark gap, a

battery not exceeding siX or eight dry cells,

and an induction coil for the same, an aerial consisting of a fine thread-like wire con nected directly to one side of said gap, a ground for said aerial, a current separator in series with said aerial and connected directly with saidv ground, and a suitable` receiving apparatus, substantially as described.

17 In a wireless telegraphic apparatus,

lthe combination of a Wave transmitter, a

receiving and sending aerial circuit connected thereto, a ground for the same, and a current separator and an adjustable ca acity in said circuit, substantially as descri ed.

18. In-..a portable wireless telegraphic apparatus, the combination of a suitable wave transmitter, a receiving and Isending aerial circuit directly connected thereto, -a ground for the same, a current separator consisting essentially of carborundum, and an adjustable capacity in said circuit, substantially as described. i

l 19. In a portable wireless telegraphic apparatus, thevv combination of a suitable wave transmitter, a receiving and sending aerial circuit directly connected thereto, a ground for the same, al current separator consisting essentially of carborundum, and an adjustable capacity in said circuit connected to said ground, substantiall as described.

20. In a portable wire'ess telegraphic apparatus the combination of va'vvave transmitter a sending and receiving aerial or ground for the same, a current separator composed of carborundum in said aerial, and a receiver at all tiinescin circuit with said transmitter and connected to said ground substantially as described.

21. In a portable wireless telegraphic apparatus the combination ofa suitable Wave transmitter, a sending -and receiving aerial directly connected to the same; a ground for said aerial; an air gap in said aerial; a current separator in said aerial between said transmitter and said ground and a receiver at all times in circuit with said transmitter and connected to said ground, whereby'thc wiring is simplified and the apparatus lightencd as substantially described.

22. In an interrupter for spark coils especially adapted ,for portable wireless telcgraphic apparatus, the combination of a spring controlled armature, two electric con ta'cts a primary circuit, or controlling key, for the saine, and a short circuit connected to said primary and including said contacts substantially as described.

23. In a'wireless telegraphic apparatus the combination of a wave transmitter, an adjustable inductance connected to the same, an aerial, a rectifier in said aerial, and a plurality of spark Gaps in a shunt with said aerial substantially as described.

24. Iii a` portable wireless telegraphic apparatus capable of sending 20 miles and more, the combination of one or more spark gaps, a battery and induction coil for the same, a magneto interrupter in shunt circuit with the primaryof said induction coil, an aerial consisting of small wire suspended as described, a current rectifier in series with said aerial and connected to ground and a suitable receiving ap aratus containing a light tuner, substantia ly as described.

In testimony .whereof, I have allixed my signature, in presence of twowitnesses.

, IIALSEY DUNWOOIH'. Witnesses-z v -K. D. ALLEN, c A. G. PENDLETON. 

